Spider esters as delivery systems

ABSTRACT

The present invention is directed to the delivery of a variety of topically active materials from a class of compounds called spider esters, which are the topic of U.S. Pat. No. 7,437,707 incorporated herein by reference. According to this first aspect of the present invention, active ingredients are delivered more efficaciously to, and, where desired, through the skin (i.e., localized subdermal penetration). By “delivered more efficaciously” is meant a cream, lotion, gel or serum that is contacted with the skin such that the active ingredient(s) are delivered in a manner that has (i) the same or similar therapeutic effect but at lower dosage of the active ingredient(s), and/or (ii) the same or similar desired therapeutic effect over a longer period of time, and/or (iii) a better or improved therapeutic effect in comparison to the same dose of active ingredient(s) in another delivery vehicle.

RELATED APPLICATIONS

This application is a continuation in part of publication US 20080319069filed Aug. 25, 2008 serial No. 22940 which is in turn a divisionalapplication of co-pending Ser. No. 11/124,018 filed May 9, 2005, nowU.S. Pat. No. 7,473,707 issued Jan. 6, 2009.

GOVERNMENT SPONSORSHIP None FIELD OF THE INVENTION

The present invention is directed to the delivery of a variety of activematerials from a class of compounds called spider esters, which are thetopic of U.S. Pat. No. 7,437,707 incorporated herein by reference.

BACKGROUND OF THE INVENTION

Surfactants are commonly used in formulating topically applied vehicles.However, surfactants are known to have irritating effects, stripping theskin of its natural oils and protective barrier. Surfactants can alsointeract with, and negatively impact, the efficacy of activeingredients. Accordingly, a first aspect of the present inventionrelates to delivery systems comprising polar esters that allow fordelivery of active ingredients to the skin in topical-applied productsthat have reduced loadings (e.g., less than about 2%) of surfactants orthat are essentially-free of surfactants.

THE INVENTION Objective of the Invention

According to this first aspect of the present invention, activeingredients are delivered more efficaciously to, and, where desired,through the skin (i.e., localized subdermal penetration). By “deliveredmore efficaciously” is meant a cream, lotion, gel or serum that iscontacted with the skin such that the active ingredient(s) are deliveredin a manner that has (i) the same or similar therapeutic effect but atlower dosage of the active ingredient(s), and/or (ii) the same orsimilar desired therapeutic effect over a longer period of time, and/or(iii) a better or improved therapeutic effect in comparison to the samedose of active ingredient(s) in another delivery vehicle.

As will be appreciated by persons of skill in the art, a system thatdelivers the same or similar therapeutic effect over a longer period oftime requires fewer administrations (i.e., dosings). This, in turn,improves patient compliance. These needs are met by the compositions ofthe present invention

A second aspect of the present invention relates to a delivery systemthat provides improved protection to the skin from ultravioletradiation.

A third aspect of the present invention relates to a method forproviding controlled release of dihydroxyacetone (“DHA”) over time. Afourth aspect of the present invention relates to reducing or maskingthe unpleasant odors associated with certain active ingredients,including DHA.

DETAILED DESCRIPTION OF THE INVENTION Delivery System

One aspect of the present application relates to a system for deliveryof dermatologic and cosmetic active ingredients from reduced surfactantemulsion systems. By reduced surfactant emulsion system is meant anoil-in-water emulsion, a water-in-oil emulsion, a water-in-siliconeemulsion, a silicone-in-water emulsion, a water-in-oil-in-water, or anoil-in-water-in-oil emulsion in which less than 2% by weight of thetotal composition is comprised of surfactants. Preferably, thesurfactant loading is less than 1.5%, even more preferably less than 1%,and still more preferably less than 0.5% by weight of the totalcomposition.

The delivery system according to this first aspect of the inventioncomprises:

-   -   (a) an oil phase comprising at least one polar ester conforming        to one of the following three structures:    -   (i)

-   -   -   wherein        -   a is an integer ranging from 0 to 4;        -   b is an integer ranging from 0 to 4, with the proviso that            a+b ranges from 1 to 4;        -   R¹ is alkyl having 7 to 21 carbon atoms;

    -   (ii)

(CH₃)_(x)—C—(CH₂—O—(CH₂CH₂O)_(a)—CH₂CH(CH₃)O)_(b)—C(O)—R¹)_(y)  (Formula2)

-   -   -   wherein a is an integer ranging from 0 to 4;        -   b is an integer ranging from 0 to 4, with the proviso that            a+b ranges from 1 to 5;        -   R¹ is alkyl having 7 to 21 carbon atoms;        -   y is 4 or 3;        -   x equals 4−y;

    -   (iii)

-   -   -   wherein

R² is —(CH₂CH₂O)_(a)—CH₂CH(CH₃)O)_(b)—C(O)—R¹

-   -   -   a is an integer ranging from 0 to 4;        -   b is an integer ranging from 0 to 4, with the proviso that            a+b ranges from 1 to 5;        -   R¹ is alkyl having 7 to 21 carbon atoms;

    -   (ii) an aqueous phase;

    -   (iii) at least one surfactant at a concentration of less than        about 2%;

    -   (iv) at least one active cosmetic or dermatologic active        ingredient at a concentration sufficient to have the desired        therapeutic effect.

Suitable surfactants are described in McCutcheon's Detergents andEmulsifiers (1986) and O'Lenick, Surfactants:Chemistty and Properties(1999).

Representative polar esters conforming to Formulas 1-3 are registeredwith the Cosmetics Fragrance & Toiletries Association and have beenassigned the following INCI names: Sorbeth-2 Hexaisostearate; Sorbeth-2Hexacaprylate/Caprate Sorbeth-2 Hexylaurate; Hydroxypropyl DimethiconeStearate; Hydroxypropyl Dimehticone Isostearate; Sorbeth-2 Hexaoleate;Glycereth-6 Tricocoate; Sorbeth-12 Hexacocoate; Glycereth-6 Trioleate.

Another aspect of the present invention is directed to an anhydrousdelivery system comprising:

-   -   (a) at least one polar ester conforming to Formula 1, Formula 2        or Formula 3;    -   (b) at least one hydrophobic or lipophilic ingredient selected        from the group consisting of:        -   (i) a volatile linear silicone oil conforming to the            following structure:

(CH₃)₃—Si—O—[Si(CH₃—O]_(x)—Si(CH₃)₃

-   -   -   -   wherein x is an integer from 0 to 7, preferably from 0                to 5;

        -   (ii) a cyclic volatile silicone oil conforming to the            following structure:

-   -   -   -   wherein y is an integer from 3 to 6.

        -   (iii) a volatile straight or branched chain paraffinic            hydrocarbon oil having 5 to 40 carbon atoms;

        -   (iv) a non-volatile silicone oil, preferably have a            viscosity ranging of from about 20 to 100,000 centistokes at            25° C.;

        -   (v) nonvolatile hydrocarbon oils including, but not limited            to, isoparaffins and olefins having greater than 20 carbon            atoms;

        -   (vi) a cosmetically-acceptable ester as described below;

        -   (vii) glyceryl esters of fatty acids or triglycerides,            derived from animal or vegetable sources, non-limiting            examples of which include castor oil, lanolin oil, C₁₀₋₁₈            triglycerides, caprylic/capric triglycerides, coconut oil,            corn oil, cottonseed oil, sesame oil, olive oil, palm oil,            peanut oil, rapeseed oil, soybean oil, safflower oil,            sunflower seed oil and walnut oil, and derivatives thereof;

        -   (viii) fluorinated oils including, but not limited to,            fluorinated silicones, fluorinated esters and            perfluoropolyethers.

        -   (ix) guerbet esters formed by the reaction of a carboxylic            acid with a guerbet alcohol.

    -   (c) at least one active cosmetic or dermatologic active        ingredient at a concentration sufficient to have the desired        therapeutic effect.

As used herein, the term “volatile oil” means an oil that is pourableliquid at room temperature and has a vapor pressure of at least about 2mm. of mercury at 20° C.

As used herein, the term “non-volatile oil” means an oil that ispourable liquid at room temperature and has a vapor pressure of lessthan about 2 mm. of mercury at 20° C.

As used herein, “cosmetically-acceptable ester” refers to compoundsformed by the reaction of a mono-, di- or tri-carboxylic acid with analiphatic or aromatic alcohol that are not irritating and do nototherwise have deleterious effects when applied to the skin. Thecarboxylic acid may contain from 2 to 30 carbon atoms, and may bestraight-chain or branched-chain, saturated or unsaturated. Thecarboxylic acid may also be substituted with one or more hydroxylgroups. The aliphatic or aromatic alcohol may contain 2 to 30 carbonatoms, may be straight-chain or branched-chain, saturated or unsaturatedform. The aliphatic or aromatic alcohol may contain one or moresubstituents including, for example a hydroxyl.

Actives

Hydrophilic hydroxycarboxylic acids suitable actives for use incompositions of the present invention include alpha hydroxy acids (AHAs)and polyhydroxyacids (PHAs).

AHAs are a group of hydroxy acids in which the hydroxy group is attachedto the alpha carbon atom of the acid. They conform to the structure:(R₁)(R₂)C(OH) COOH, where R₁ and R₂ are selected from the groupconsisting of hydrogen, alkyl, aralkyl and aryl groups, the lattergroups having 1-29 carbon atoms. The alkyl, aralkyl and aryl groups maybe saturated or unsaturated, isomeric or non-isomeric, straight orbranched chain or cyclic. The alkyl, aralkyl and aryl groups may alsocontain as substituents OH, CHO, COOH and alkoxy groups having 1 to 9carbon atoms. In addition, R₁ and R₂ may also Cl, Br, I, S, F, or analkyl or alkoxy group, saturated or unsaturated, having 1 to 9 carbonatoms.

As used in the present application, the term “AHA” means the free acid,its corresponding ester (formed by reaction of the AHA with an alcohol),its corresponding lactone (formed by the reaction of the carboxylic acidand hydroxyl groups of the AHA), as well as its corresponding salt(formed by reaction of the AHA with an organic base or an inorganicalkali). R₁ and R₂ may be the same or different. In the latter case, theAHAs may be stereoisomers in the D, L, and DL forms. AHAs suitable foruse in the present invention may be grouped into (i) alkyl AHAs, (ii)aralkyl and aryl AHAs, (iii) polyhydroxy AHAs, and (iv) polycarboxylicAHAs.

Alkyl AHAs (i.e., where R₁ and R₂ are hydrogen or alkyl) suitable foruse in compositions of the present invention include: 2-hydroxyethanoicacid (glycolic acid, hydroxyacetic acid); 2-hydroxypropanoic acid(lactic acid); 2-methyl 2-hydroxypropanoic acid (methyllactic acid);2-hydroxybutanoic acid; 2-hydroxypentanoic acid; 2-hydroxyhexanoic acid;2-hydroxyheptanoic acid; 2-hydroxyoctanoic acid; 2-hydroxynonanoic acid;2-hydroxydecanoic acid; 2-hydroxyundecanoic acid; 2-hydroxydodecanoicacid (alpha hydroxylauric acid); 2-hydroxytetradecanoic acid (alphahydroxymyristic acid); 2-hydroxyhexadecanoic acid (alpha hydroxypalmiticacid); 2-hydroxyoctadecanoic acid (alpha hydroxystearic acid);2-hydroxyeicosanoic acid (alpha hydroxyarachidonic acid).

Aralkyl and aryl AHAs (i.e., where R₁ and R₂ are arylalkyl or aryl)suitable for use in compositions of the present invention include:2-phenyl 2-hydroxyethanoic acid (mandelic acid); 2,2-diphenyl2-hydroxyethanoic acid (benzilic acid); 3-phenyl 2-hydroxypropanoic acid(phenyl)acetic acid); 2-phenyl 2-methyl 2-hydroxyethanoic acid(atrolactic acid, 2-(4′-hydroxyphenyl); 2-hydroxyethanoic acid(4-hydroxymandelic acid); 2-(4′-chlorophenyl) 2-hydroxyethanoic acid(4-chloromandelic acid); 2-(3′-hydroxy-4′-methoxyphenyl)2-hydroxyethanoic acid (3-hydroxy-4-methoxymandelic acid);2-(4′-hydroxy-3′-methoxyphenyl); 2-hydroxyethanoic acid(4-hydroxy-3-methoxymandelic acid); 3-(2′-hydroxyphenyl);2-hydroxypropanoic acid (3-(2′-hydroxyphenyl) lactic acid);3-(4′-hydroxyphenyl) 2-hydroxypropanoic acid (3-(4′-hydroxyphenyl)lactic acid)); 2-(3′,4′-dihydroxyphenyl) 2-hydroxyethanoic acid(3,4-dihydroxymandelic acid).

Polyhydroxy AHAs suitable for use in compositions the present inventioninclude: 2,3-dihydroxypropanoic acid (glyceric acid);2,3,4-trihydroxybutanoic acid and its isomers (erythronic acid, threonicacid); 2,3,4,5-tetrahydroxypentanoic acid and its isomers (ribonic acid,arabinoic acid, xylonic acid, lyxonic acid);2,3,4,5,6-pentahydroxyhexanoic acid and its isomers (allonic acid,altronic acid, gluconic acid, mannoic acid, gulonic acid, idonic acid,galactonic acid, talonic acid); 2,3,4,5,6,7-hexahydroxyheptanoic acidand its isomers (glucoheptonic acid, galactoheptonic acid).

Polycarboxylic AHAs suitable for use in compositions of the presentinvention include: 2-hydroxypropane-1,3-dioic acid (tartronic acid);2-hydroxybutane-1,4-dioic acid (malic acid);2,3-dihydroxybutane-1,4-dioic acid (tartaric acid);2-hydroxy-2-carboxypentane-1,5-dioic acid (citric acid);2,3,4,5-tetrahydroxyhexane-1,6-dioic acid and its isomers (saccharicacid, mucic acid).

In a preferred embodiment of the delivery system of the presentinvention, the AHA is monocarboxylic and is selected from the groupconsisting of glycolic acid, lactic acid, and mandelic acid.

In another preferred embodiment of the delivery system of the presentinvention, the AHA is polycarboxylic and is selected from the groupconsisting of malic acid, tartaric acid and citric acid.

In yet another embodiment of the delivery system of the presentinvention, the hydroxy acid is a polyhydroxy acid. In a preferredembodiment, the polyhydroxy acid is selected from the group consistingof gluconolactone and lactobionic acid

Hydrophilic hydroxycarboxylicacids are used in the delivery systems ofthe present invention at concentrations ranging from about 0.1% to about6%, preferably from about 0.2% to about 4%, and more preferably fromabout 0.5% to about 3%.

Compositions of the present invention may also be used to delivertherapeutically effective amounts of pharmaceutical ingredients used totreat the following conditions associated with exposure to ultravioletradiation: actinic keratoses; basal cell carcinoma; squamous cellcarcinoma; melanoma.

With respect to the treatment of actinic keratoses, non-limitingexamples of pharamaceutical ingredients may be topically-delivered fromthe compositions of the present invention include: Aciretin; Adapalene;Diclofenac in combination with Hyaluronic Acid; Fluourouracil;Imiquimod; Salicylic Acid.

Compositions according to the present invention may be used to deliverprescription and non-prescription anti-inflammatory agents to the skin.The term “non-prescription” includes, but is not limited to, ingredientsgenerally recognized as safe and effective under an applicableover-the-counter monograph issued by the FDA. Both steroidal andnon-steroidal anti-inflammatory agents may be formulated in anddelivered from compositions of the present invention. Non-limitingexamples of anti-inflammatory agents are listed below, withcorresponding doses indicated in parenthesis: Alcometasone dipropionate(0.05%); Amcinonide (0.1%); Betamethasone dipropionate (0.05%);Betamethasone valerate (0.01%); Clobetasol propionate (0.05%);Clocortolone pivalate (0.1%); Desometasone (0.05%); Desonide (0.05%);Diflorasone diacetate (0.05%); Diflorasone diacetate (0.25%);Flocinonide (0.05%); Fluocinolone acetonide (0.025%); Fluoranenolide(0.05%); Fluticasone (0.05%); Fluticasone propionate (0.005%);Halbetasol propionate (0.05%); Halcinonide (0.1%); Hydrocortisone(0.5%); Hydrocortisone valerate (0.1%); Hydrocortisone butyrate (0.1%);Hydrocortisone valerate (0.2%); Mometasone furoate (0.1%); Mometasonefuroate (0.1%); Prednicarbate (0.025%); Triamcinolone acetonide (0.5%).

Another aspect of the present invention is directed to the topicaldelivery of active ingredients useful in treating erythema multiforme.These include the steroidal and non-steroidal anti-inflammatory agentslisted above.

A still further aspect of the present invention is directed to thetopical delivery of active ingredients useful in treating rosacea.Non-limiting examples of such ingredients include the following: Azelaicacid; Benzoyl peroxide; Clindamycin; Doxycycline or Minocycline;Erythromycin; Isotretinoin; Metronidazole; Permethrin; Sodiumsulfacetamide; Sulfur; Tacrolimus; Tetracycline; Tretinoin.

Benign photodamage manifested as hyperpigmentation may be treatedthrough topical application of hydroquinone, kojic acid, glycolic acidand other alpha-hydroxy acids, ascorbic acid, magnesium ascorbylphosphate, ascorbyl glucosamine and artocarpin. These “skin-lightening”active ingredients may be incorporated into and delivered from thecompositions of the present invention.

Recently, in light of concerns raised about the safety of hydroquinone,there has emerged a need for alternative, preferably,botanically-derived skin lightening agents. Accordingly, another aspectof the present invention is directed to delivering botanically-derivedingredient, including particularly flavanoids derived from botanicalsources, to the skin in compositions of the present invention.

Compositions of the present invention may be used to deliver ingredientsuseful in the treatment of acne including, but not limited to, thefollowing: Adapalene; Alpha-hydroxy acids; Azelaic acid; Benzoylperoxide; Cimetidine; Clindamycin; Erythromycin; Resorcinol; SalicylicAcid; Tazarotene; Tretinoin. Further examples of suitable anti-acneactives are described in U.S. Pat. No. 5,607,980.

Antitpruritic agents known to those of skill in the art, including thoselisted below, may be delivered to the skin in topically-applied productscomprising the compositions of the present invention: Doxepin;Pramoxine.

Compositions of the present invention may be used to deliver ingredientsuseful in the treatment of alopecia areata and androgenic alopecia, orotherwise helping to reduce hair loss, stop hair loss or stimulate hairgrowth. These include, but are not limited to, the following:5-alpha-reductase inhibitors and other antiandrogenic compounds such asFlutamide, Cyproterone and Spironolactone; Cimetidine; Finasteride; andMinoxidil.

A still further aspect of the present invention is directed to deliveryto the skin of active ingredients that remove hair including, but notlimited to, thioglycolates and eflornithine HCl.

Yet another aspect of the present invention is directed to the topicaldelivery of active ingredients useful in treating warts including, butnot limited to the following: Dinitrochlorobenzene;Diphenylcyclopropenone; 5-Fluoracil; Glutaraldehyde; Imiquimod Mono-,di-, tri-chloroacetic acid; Podophyllin; Polofilox; Salicylic Acid.

The present application is also directed to the topical delivery ofactive ingredients that promoting wound healing.

Compositions of the present invention may also be used to delivertopical analgesic agents including, but not limited to, corticosteroids,lidocaine, benzocaine, prilocaine, dibucaine tetracaine, butamben,pramoxine, benzyl alcohol, menthol, wintergreen oil, eucalyptus oil,capsaicin, trolamine salicylate, and mixtures thereof.

Another aspect of the present invention is directed to topicalantifungal and antimicrobial agents known to those of skill in the art,including those listed below, which may be delivered to the skin intopically-applied products comprising the compositions of the presentinvention. Non-limiting examples of antimicrobial and antifungal agentssuitable for use in the present invention include: β-lactam agents,quinolone agents, ciprofloxacin, norfloxacin, tetracycline,erythromycin, amikacin, 2,4,4′-trichloro-2′-hydroxy diphenyl ether,3,4,4′-trichlorobanilide, phenoxyethanol, phenoxy propanol,phenoxyisopropanol, doxycycline, capreomycin, chlorhexidine,chlortetracycline, oxytetracycline, clindamycin, ethambutol, hexamidineisethionate, metronidazole, pentamidine, gentamicin, kanamycin,lincomycin, methacycline, methenamine, minocycline, neomycin,netilmicin, paromomycin, streptomycin, tobramycin, miconazole,tetracycline hydrochloride, erythromycin, zinc erythromycin,erythromycin estolate, erythromycin stearate, amikacin sulfate,doxycycline hydrochloride, capreomycin sulfate, chlorhexidine gluconate,chlorhexidine hydrochloride, chlortetracycline hydrochloride,oxytetracycline hydrochloride, clindamycin hydrochloride, ethambutolhydrochloride, metronidazole hydrochloride, pentamidine hydrochloride,gentamicin sulfate, kanamycin sulfate, lineomycin hydrochloride,methacycline hydrochloride, methenamine hippurate, methenaminemandelate, minocycline hydrochloride, neomycin sulfate, netilmicinsulfate, paromomycin sulfate, streptomycin sulfate, tobramycin sulfate,miconazole hydrochloride, ketaconazole, amanfadine hydrochloride,amanfadine sulfate, octopirox, parachlorometa xylenol, nystatin,tolnaftate, zinc pyrithione and clotrimazole.

Compositions of the present invention may also be used to deliver agentsthat reduce cellulite including xanthine compounds such as caffeine,theophylline, theobromine, and aminophylline.

The International Cosmetic Ingredient Dictionary and Handbook publishedby the Cosmetics Fragrance and Toiletries Association describes a widevariety of non-limiting ingredients used in topically-applied products,both cosmetic and dermatologic, which may be delivered from thecompositions of the present invention. These include antioxidants, skinsoothing and/or healing agents, vitamins and derivatives thereof, andshort-chain peptides, non-limiting examples of which are enumeratedbelow. Further examples of cosmetic and/or pharmaceutical ingredientswhich are suitable for use in the delivery system of the presentinvention are disclosed in U.S. Pat. Nos. 6,492,326 and 6,277,892 andU.S. Patent Application Publication No. 2005/0142095. Additional activeingredients that may be delivered through the compositions of thepresent invention are described in Kerdel, et al., DermatologicTherapeutics (2005), and in Hardman et al., Goodman & Gilman's: ThePharmacological Basis of Therapeutics (10 Edition, 2001).

Non-limiting examples of antioxidants/radical scavengers which may betopically delivered in the present invention include: ascorbic acid(vitamin C) and its salts; ascorbyl esters of fatty acids, ascorbic acidderivatives (e.g., magnesium ascorbyl phosphate, sodium ascorbylphosphate, ascorbyl sorbate); tocopherol (vitamin E), tocopherolsorbate, tocopherol acetate, other esters of tocopherol; butylatedhydroxybenzoic acids and their salts;6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; gallic acid andits alkyl esters, especially propyl gallate; uric acid and its salts andalkyl esters; sorbic acid and its salts; lipoic acid; amines (e.g.,N,N-diethylhydroxylamine, amino-guanidine); sulfhydryl compounds (e.g.,glutathione); coenzyme Q10 and its analogues, including withoutlimitation, idebenone; dihydroxyfumaric acid and its salts; lycinepidolate; arginine pilolate; nordihydroguaiaretic acid; bioflavonoids;curcumin, lysine; 1-methionine; proline; superoxide dismutase;silymarin; tea extracts; grape skin/seed extracts; melanin; and rosemaryextracts.

Non-limiting examples of skin soothing and/or healing agents suitablefor use in the present invention include: panthenol and derivatives,aloe vera and its derivatives, pantothenic acid and its derivatives,allantoin, bisabolol, and dipotassium glycyrrhizinate.

Improved Efficiency Sunscreen Compositions

Sunscreen active ingredients provide protection to the skin by blocking,scattering, absorbing or otherwise attenuating ultraviolet radiation UVRwithin the wavelength range of from 290 nm to 400 nm. One method forimproving the efficacy of sunscreen actives in providing protection fromUVR is to keep the actives on the skin for longer periods of time. Thisneed is met by the compositions of the present invention.

Without wishing to be bound by a theory, it is believed that polargroups on sunscreen actives have a lower free energy within thecompositions of the present invention than on the surface of the skin.Put differently, sunscreen actives have a greater affinity for the polaresters of the present invention and find it energetically more favorableto remain within the claimed compositions. Thus, it is believed that byincorporating sunscreen actives into the compositions of the presentinvention, formulators can achieve a higher degree of UVR protection perunit weight of sunscreen active.

The medical and scientific literature contains reports that certainorganic sunscreens and/or their breakdown products penetrate the skinand that these chemicals may have adverse health effects. Another objectof the present invention is therefore to provide a desired SPF with alesser amount of organic sunscreens and, in so doing, reducing the riskthat the user may later develop an adverse health effect associated withsystemic absorption of sunscreen actives or their breakdown product.Relatedly, it is believed that the degree of penetration of sunscreenactives will be lessened by being incorporated into compositions of thepresent invention.

Accordingly, a second aspect of the present invention is directed toreduced surfactant emulsion systems and anhydrous systems as describedabove further comprising an organic sunscreen having at least one polar(i.e., charged) group.

Organic sunscreens having at least one polar group include those whichare currently approved by the US Food and Drug Administration in theSunscreen Drug Products for Over-The-Counter Human Use Final Monographas published in the Federal Register on May 21, 1999 at Volume 64,Number 98, pages 27666-27693. Organic sunscreens currently approved bythe FDA are as follows: p-Aminobenzoic acid (PABA) up to 15%; Avobenzoneup to 3%; Cinoxate up to 3%; Dioxybenzone up to 3%; Homosalate up to15%; Menthyl anthranilate up to 5%; Octocrylene up to 10%; Octylmethoxycinnamate (Octinoxate) up to 7.5%; Octyl salicylate up to 5%;Oxybenzone up to 6%; Padimate O up to 8%; Phenylbenzimidazole sulfonicacid (Ensulizole) up to 4%; Sulisobenzone up to 10%; Trolaminesalicylate up to 12%.

Other suitable sunscreen active ingredients are approved in countriesoutside the US are also considered to be suitable for use withcompositions of the present invention. Non-limiting examples of suchorganic sunscreen actives include the following: 4-Methylbenzylidenecamphor (USAN Enzacamene); Methylene Bis-BenzotriazolylTetramethylbutylphenol (USAN Bisoctrizole) marketed under the tradenameTinosorb® M; Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine (USANBemotrizinol) marketed under the tradename marketed under the tradenameTinosorb® S; Terephthalylidene Dicamphor Sulfonic Acid (USAN Ecamsule)marketed under the tradename Mexoryl® SX; Drometrizole Trisiloxanemarketed under the tradename Mexoryl® XL; Disodium PhenylDibenzimidazole Tetrasulfonate marketed under the tradename NeoHeliopan® AP; Diethylamino Hydroxybenzoyl Hexyl Benzoate marketed underthe tradename Uvinul® A Plus; Octyl Triazone marketed under thetradename Uvinul® T 150; Diethylhexyl Butamido Triazone marketed underthe tradename Uvasorb® HEB; Polysilicone-15 marketed under the tradenameParsol® SLX.

Self-Tanner

Another aspect of the present invention is related to the delivery ofself-tanning actives to the skin. Surprisingly, and unexpectedly, it hasbeen found that when dihydroxyacetone (“DHA”) is incorporated intocompositions of the present invention, the characteristic burnt caramelsmell often associated with DHA is reduced.

A related and still more surprising and unexpected finding is that thehigh relative degree of affinity of DHA for the compositions of thepresent invention allows for controlled release of DHA over time. Moreparticularly, it has been found that the rate of release of DHA can becontrolled by selecting different glyceryl esters of fatty acids ortriglycerides for inclusion in finished formulations (e.g., creams,lotions, serums anhydrous gels). Non-limiting examples of glycerylesters of fatty acids or triglycerides that may be included in finishedformulations comprising compositions of the present invention includecastor oil, lanolin oil, coconut oil, corn oil, cottonseed oil, sesameoil, olive oil, palm oil, peanut oil, rapeseed oil, soybean oil,safflower oil, sunflower seed oil and walnut oil, and derivativesthereof.

Odor Reduction

A still further aspect of the present invention is the ability toreduce, sequester or otherwise mitigate unpleasant odor characteristicsknown by those of skill in the art to be associated with certaincosmetic or dermatologic ingredients.

As is well-known to those of skill in the art, volatile organic orinorganic compounds which contain at least one of the following elementsproduce a noxious or otherwise unpleasant smell or odor: nitrogen,phosphorus, oxygen, sulfur, fluorine, chlorine, bromine, or iodine. Itis also well-known that certain unsaturated or aromatic hydrocarbons ora saturated or unsaturated aldehydes or ketones produce an unpleasantodor. It is particularly well-known that the following chemicals producean unpleasant odor: ammonia; hydrogen sulfide; acetic acid, propionicacid, butyric acid, isobutyric acid, valeric acid, isovaleric acid,caproic acid, heptanoic acid, lauric acid, pelargonic acid; cyclic oracyclic hydrocarbons which contain nitrogen or sulfur; saturated orunsaturated aldehydes (e.g., hexanal, heptanal, octanal, nonanal,decanal, octenal, or nonenal); and volatile aldehydes (butyraldehyde,propionaldehyde, acetaldehyde, and formaldehyde).

Combining the above-listed ingredients with the esters of Formulas 1, 2or 3, surprisingly and unexpectedly reduces, sequesters or otherwisemitigates the unpleasant odor characteristics of these substances.

While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthhereinabove but rather that the claims be construed as encompassing allthe features of patentable novelty which reside in the presentinvention, including all features which would be treated as equivalentsthereof by those skilled in the art to which the invention pertains.

1. A delivery system which comprises: (a) an oil phase comprising atleast one polar ester conforming to one of the following threestructures: (i)

wherein a is an integer ranging from 0 to 4; b is an integer rangingfrom 0 to 4, with the proviso that a+b ranges from 1 to 4; R¹ is alkylhaving 7 to 21 carbon atoms; (ii)(CH₃)_(x)—C—(CH₂—O—(CH₂CH₂O)_(a)—CH₂CH(CH₃)O)_(b)—C(O)—R¹)_(y) wherein ais an integer ranging from 0 to 4; b is an integer ranging from 0 to 4,with the proviso that a+b ranges from 1 to 5; R¹ is alkyl having 7 to 21carbon atoms; y is 4 or 3; x equals 4−y; (iii)

whereinR² is —(CH₂CH₂O)_(a)—CH₂CH(CH₃)O)_(b)—C(O)—R¹ a is an integer rangingfrom 0 to 4; b is an integer ranging from 0 to 4, with the proviso thata+b ranges from 1 to 5; R¹ is alkyl having 7 to 21 carbon atoms; (v) anaqueous phase; (vi) at least one surfactant at a concentration of lessthan about 2%; (vii) at least one active cosmetic or dermatologic activeingredient at a concentration sufficient to have the desired therapeuticeffect. (a) an oil phase comprising at least one polar ester conformingto one of the following three structures: (i)

wherein a is an integer ranging from 0 to 4; b is an integer rangingfrom 0 to 4, with the proviso that a+b ranges from 1 to 4; R¹ is alkylhaving 7 to 21 carbon atoms; (ii)(CH₃)_(x)—C—(CH₂—O—(CH₂CH₂O)_(a)—CH₂CH(CH₃)O)_(b)—C(O)—R¹)_(y) wherein ais an integer ranging from 0 to 4; b is an integer ranging from 0 to 4,with the proviso that a+b ranges from 1 to 5; R¹ is alkyl having 7 to 21carbon atoms; y is 4 or 3; x equals 4−y; (iii)

whereinR² is —(CH₂CH₂O)_(a)—CH₂CH(CH₃)O)_(b)—C(O)—R₁ a is an integer rangingfrom 0 to 4; b is an integer ranging from 0 to 4, with the proviso thata+b ranges from 1 to 5; R¹ is alkyl having 7 to 21 carbon atoms; and atleast one hydrophobic or lipophilic ingredient selected from the groupconsisting of: (i) a volatile linear silicone oil conforming to thefollowing structure:(CH₃)₃—Si—O—[Si(CH₃—O]_(x)—Si(CH₃)₃ wherein x is an integer from 0 to 7,preferably from 0 to 5; (iii) a cyclic volatile silicone oil conformingto the following structure:

wherein y is an integer from 3 to
 6. (x) a volatile straight or branchedchain paraffinic hydrocarbon oil having 5 to 40 carbon atoms; (xi) anon-volatile silicone oil, preferably have a viscosity ranging of fromabout 20 to 100,000 centistokes at 25° C.; (xii) nonvolatile hydrocarbonoils including, but not limited to, isoparaffins and olefins havinggreater than 20 carbon atoms; (xiii) a cosmetically-acceptable ester asdescribed below; (xiv) glyceryl esters of fatty acids or triglycerides,derived from animal or vegetable sources, non-limiting examples of whichinclude castor oil, lanolin oil, Cl₁₀₋₁₈ triglycerides, caprylic/caprictriglycerides, coconut oil, corn oil, cottonseed oil, sesame oil, oliveoil, palm oil, peanut oil, rapeseed oil, soybean oil, safflower oil,sunflower seed oil and walnut oil, and derivatives thereof; (xv)fluorinated oils including, but not limited to, fluorinated silicones,fluorinated esters and perfluoropolyethers. (xvi) guerbet esters formedby the reaction of a carboxylic acid with a guerbet alcohol. and (c) atleast one active cosmetic or dermatologic active ingredient at aconcentration sufficient to have the desired therapeutic effect.